All the advice is super sound and injects the confidence needed to prepare myself for that first type of phone call from the tenant.  

I am getting about 500/pier and depends on the sqft for foam injection.

You can use an "open spray foam" to injecting into all the walls of the house that are not opened up. 

On another partnership, I injected cash into as well.  

You won’t be able to inject money from outside if you are short on cash available.You can’t get involved in any repairs or active management for your property as it would be an illegal contribution and the IRS will disallow your tax shelter.In case of liability arising from your property you may loose the totality of your retirement plan.

Also look for the clause that talks about additional capital raises - if the deal requires new capital injection, are the limited partners on the hook for new capital. 

If you contact a foundation repair company they have a material that they inject under the concrete that will raise it up even, then you just have a minor cement repair that can be masked with a rough finish on the entire porch.Or remove it and put in a wood porch.

Doe the property require an immediate cash injection to get things going or is it something that can be gradually dealt with from the profits of the property?

- Do their cash flow projections indicate that they will remain solvent or require additional capital injection at some point prior to profitability?

Leaving $70k on the table by not injecting $30k into the property seems a bit rash, but seller's do weird things.